Bragg gratings and Fabry-Perot interferometers on an Er-MgO-doped optical fiber

Abstract In this paper, the fabrication of fiber Bragg gratings (FBGs) and intrinsic Fabry-Perot interferometers (IFPIs) on an Er-MgO-doped silica optical fiber is reported. The inscription of both sensing devices was performed by means of a femtosecond laser, using the phase mask method to inscribe the FBG and a micromachining platform for the IFPI. Thermal and strain characterizations were performed for both devices, achieving the maximum sensitivities of 12.57 pm/°C and 0.85 pm/µe for the FBG case, and 10.2 pm/°C and 0.91 pm/µe for the IFPI. A high temperature experiment was conducted to assess the thermal behavior of the inscribed FBG, revealing sensing capabilities for temperatures up to 700 °C. The results confirm that this new type of fiber will have an important role on the development of new optoelectronic devices, such as fiber lasers, optical amplifiers and sensors.